A new Lenstra-type Algorithm for Quasiconvex Polynomial Integer Minimization with Complexity 2^O(n log n)

We study the integer minimization of a quasiconvex polynomial with quasiconvex polynomial constraints. We propose a new algorithm that is an improvement upon the best known algorithm due to Heinz (Journal of Complexity, 2005). This improvement is achieved by applying a new modern Lenstra-type algorithm, finding optimal ellipsoid roundings, and considering sparse encodings of polynomials. For the bounded case, our algorithm attains a time-complexity of s (r l M d)^{O(1)} 2^{2n log_2(n) + O(n)} when M is a bound on the number of monomials in each polynomial and r is the binary encoding length of a bound on the feasible region. In the general case, s l^{O(1)} d^{O(n)} 2^{2n log_2(n) +O(n)}. In each we assume d>= 2 is a bound on the total degree of the polynomials and l bounds the maximum binary encoding size of the input.Comment: 28 pages, 10 figure

Bounds on Subspace Codes Based on Subspaces of Type (

The Sphere-packing bound, Singleton bound, Wang-Xing-Safavi-Naini bound, Johnson bound, and Gilbert-Varshamov bound on the subspace codes n+l,M,d,(m,1)q based on subspaces of type (m,1) in singular linear space Fq(n+l) over finite fields Fq are presented. Then, we prove that codes based on subspaces of type (m,1) in singular linear space attain the Wang-Xing-Safavi-Naini bound if and only if they are certain Steiner structures in Fq(n+l)

Critères d'induction et de coinduction pour certains anneaux d'opérateurs différentiels

RésuméSoit L une algèbre de Lie opérant par dérivations sur un anneau local commutatif noethérien (R,M,K=R/M), et soit V l'anneau des opérateurs différentiels construits à partir de R et L. Posons L(M)={d∈L/d(M)⊂M} et L0 = L(M)/ML: L0 est une algèbre de Lie qui opère sur K par dérivations et l'on peut construire un anneau d'opérateurs différentiels sur K à l'aide de L0, noté V0. Grâce au (V0 − V)-bimodule V/MV on définit l'induction (resp. la coinduction) de V0 à V par IndVv0=−⊗v0V/MV (resp. CoindVv0=Homv0(V/MV,−)) et on donne un critère pour qu'un V-module soit induit (resp. coinduit) à partir de V0. Ces résultats sont des analogues de ceux, établis par Mackey pour les groupes de Lie et par Blattner pour les algèbres de Lie, analogues, basés sur la notion de système d'imprimitivité.AbstractLet L be a Lie algebra acting by derivations on a commutative noetherian local ring (R,M,K=R/M) and let V be the ring of differential operators built on R and L. Defining L(M)={d∈L/d(M)⊂M} et L0 = L(M)/ML: L0 is a Lie algebra which acts on K by derivations, and we can construct a differential operators ring on K with L0, denoted by V0. With the help of the (V0 − V)-bimodule V/MV we define the induction (resp. coinduction) from V0 to V by IndVv0=−⊗v0V/MV and we give a criterion for a V-module to be induced (resp. coinduced) from V0. These results are similar to those established by Mackey for Lie groups and Blattner for Lie algebras, which are based on the notion of the system of imprimitivity

Large ferro–pyro–phototronic effect in 0.5Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 thin films integrated on silicon for photodetection

Coupling together the ferroelectric, pyroelectric, and photovoltaic characteristics within a single material is a novel way to improve the performance of photodetectors. In this work, we take advantage of the triple multifunctionality shown by 0.5Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (BCZT), as demonstrated in an Al/Si/SiOx/BCZT/ITO thin-film device. The Si/SiOx acts as an n-type layer to form a metal–ferroelectric–insulator–semiconductor heterostructure with the BCZT, and with Al and ITO as electrodes. The photo-response of the device, with excitation from a violet laser (405 nm wavelength), is carefully investigated, and it is shown that the photodetector performance is invariant with the chopper frequency owing to the pyro-phototronic effect, which corresponds to the coupling together of the pyroelectric and photovoltaic responses. However, the photodetector performance was significantly better than that of the devices operating based only on the pyro-phototronic effect by a factor of 4, due to the presence of ferroelectricity in the system. Thus, after a poling voltage of −15 V, for a laser power density of 230 mW/cm2 and at a chopper frequency of 400 Hz, optimized responsivity, detectivity, and sensitivity values of 13.1 mA/W, 1.7 × 1010 Jones, and 26.9, respectively, are achieved. Furthermore, ultrafast rise and fall times of 2.4 and 1.5 µs, respectively, are obtained, which are 35,000 and 36,000 times faster rise and fall responses, respectively, than previous reports of devices with the ferro–pyro–phototronic effect. This is understood based on the much faster ferroelectric switching in ferroelectric thin films owing to the predominant 180° domains in a single direction out of plane.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contracts UIDB/04650/2020. This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 958174 (M-ERA-NET3/0003/2021—NanOx4EStor). The authors would also like to thank engineer José Santos for technical support at the Thin Film Laboratory. J. L. M.-D. and R. L. Z. H. are grateful for EPSRC CAM-IES grant EP/P007767/. R. L. Z. H. also acknowledges support from the Royal Academy of Engineering under the Research Fellowships scheme (No.: RF\201718\1701). J. L. M.-D. acknowledges support from the Royal Academy of Engineering Chair in Emerging Technologies scheme (No.: CIET1819_24) and the ERC grant EROS, EU-H2020-ERC-ADG # 882929

Evaluación del potencial de un sistema de vermifiltración mediante el uso de lombrices de tierra (Eisenia fétida) para el tratamiento de aguas residuales a escala de laboratorio

La filtración utilizando lombrices de tierra vermifiltración, se utiliza como tratamiento secundario para el tratamiento de aguas residuales, donde el cuerpo de la lombriz funciona como un filtro biológico por medio del mecanismo de la ingestión y la biodegradación de residuos orgánicos. En este trabajo se realizó la evaluación de un sistema de vermifiltración, a escala de laboratorio, para depurar aguas residuales, empleando agua residual sintética con concentraciones promedio de 1776 mg DQO/l, 1027 mg DBO/l y 221 mg SST/l y aplicando tres cargas hidráulicas superficiales (13, 20 y 27 l/m²*d). Los valores obtenidos de eficiencia de remoción para los parámetros de DQO, DBO y SST, para la máxima carga aplicada son de 72%, 71% y 84% respectivamente. Comparando el sistema de vermifiltración con un sistema de filtración convencional se obtiene con cargas altas (27 l/m²*d) las mismas eficiencias de remoción para DBO, DQO y SST. Sin embargo el sistema convencional tiende a reducir su eficiencia al incrementar la carga hidráulica aplicada, mientras que el vermifiltro tiende a aumentarla. En el vermifiltro se supone, que las lombrices de tierra muelen el limo y arena, aumentando la superficie específica total, lo cual mejora la capacidad de "adsorber" los compuestos orgánicos e inorgánicos de las aguas residuales y, adicionalmente, no hay formación de lodos que en comparación con un sistema convencional implicaría un gasto adicional.Abstract Filtration using earthworms, known as vermifiltration is utilized as secondary treatment used for wastewaters, in which the worm body works as a biological filter through the mechanism of ingestion and biodegradation of organic waste. This work carried out the evaluation of the potential of a laboratory-scale vermifiltration system to purify waste water, using synthetic wastewater with average concentration of 1776 mg COD/l, 1027 mg BOD/l and 221 mg TSS/l and applying three hydraulic charges per surface (13, 20 and 27 l/m ²*d). Values obtained of removal efficiency for the COD, BOD and TSS parameters, for the maximum applied load are 72%, 71% and 84% respectively. Comparing the vermifilter system with a conventional filtration system, it is obtained with high organic loads (27 l/m²*d) the same removal efficiencies for the COD, BOD and TSS. However, the conventional system tends to reduce its efficiency by increasing the hydraulic load applied, while the vermifilter tends to increase it However, the conventional system tends to reduce its efficiency by increasing the hydraulic load applied, while the vermifilter tends to increase it. Inside vermifilter it is assumed, earthworms grind silt and sand, increasing the total specific surface area, which improves the ability to "adsorb" organic and inorganic compounds of wastewater and additionally there is no sludge formation, which compared to conventional system involves additional expenses.Maestrí

Antiferromagnetic Order in MnO Spherical Nanoparticles

We have performed unpolarized and polarized neutron diffraction experiments on monodisperse 8 nm and 13 nm antiferromagnetic MnO nanoparticles. For the 8 nm sample, the antiferromagnetic transition temperature $T_N$ (114 K) is suppressed compared to the bulk material (119 K) while for the 13 nm sample $T_N$ (120 K) is comparable to the bulk. The neutron diffraction data of the nanoparticles is well described using the bulk MnO magnetic structure but with a substantially reduced average magnetic moment of 4.2$\pm$0.3 $\mu_B$/Mn for the 8 nm sample and 3.9$\pm$0.2 $\mu_B$/Mn for the 13 nm sample. An analysis of the polarized neutron data on both samples shows that in an individual MnO nanoparticle about 80$$ of Mn ions order. These results can be explained by a structure in which the monodisperse nanoparticles studied here have a core that behaves similar to the bulk with a surface layer which does not contribute significantly to the magnetic order.Comment: 7 pages, 5 figure

Hybrid verification integrating HOL theorem proving with MDG model checking

In this paper, we describe a hybrid tool for hardware formal verification that links the HOL (higher-order logic) theorem prover and the MDG (multiway decision graphs) model checker. Our tool supports abstract datatypes and uninterpreted function symbols available in MDG, allowing the verification of high-level specifications. The hybrid tool, HOL-MDG, is based on an embedding in HOL of the grammar of the hardware modeling language, MDG-HDL, as well as an embedding of the first-order temporal logic L"m"d"g used to express properties for the MDG model checker. Verification with the hybrid tool is faster and more tractable than using either tools separately. We hence obtain the advantages of both verification paradigms

Limitation of Actions—Condition Precedent; Pensions—Vested Rights—Survival to Estate of Petitioner; Statutes of Limitations—Interpretations—Removal of Bar; Taxation—Compensating Use Tax—Application to Property Not Available for Purchase Within the State; Workmen\u27s Compensation—Pre-existing Disease—Injury

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Is There a Need for Tailored Graduate Programs for International Students?

International studies often present opportunities for capacity development and mentorship for students to equip them with the knowledge and skills to address the challenges in their home countries. Typically, international graduate students are drawn from diverse educational and cultural backgrounds different from those in their host countries. Adjusting to these changes might be challenging and time-consuming, thus influencing their academic journey. Understanding these challenges might provide international students the opportunity to address them in time and, where possible, seek help. In this paper, we discuss some graduate program-related challenges international students face and provide potential recommendations that might result in tailored programs. It is anticipated that such programs will effectively prepare international graduate students to adapt quickly to new conditions in their host countries and optimize the learning process while acquiring the appropriate tools for their future careers. We conducted a literature search that focused mainly on articles related to international graduate students in the US. Five challenges were explored: Cultural and language barriers, technological literacy and competency, mentorship, career development, and course structure and research priority areas. Graduate programs need to help students identify these challenges while helping them create an ideal environment for excellence. Such programs need to provide adequate support structures, making them known to students at the beginning of their programs. Although it is not feasible to change an entire educational program to accommodate all the needs of international graduate students, pressing concerns need to be identified for action

Bills of Sale—Chattel Mortgages—Conditional Bills of Sale—Filing; Criminal Law—Trial by Jury—Waiver; Evidence—Admissibility of Evidence of Past Crimes to Show Motive; Instructions to the Jury—Preponderance of the Evidence—Qualifing Words; Insurance—Breach of Cooperation Clause

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